Physical appearance and biologyEdit
Haikouichthys had a slim, streamlined body lacking any visible limbs or fins apart from an apparent dorsal fin running down its back. It also had small, black, beady eyes.
The appearance of Haikouichthys was an evolutionary landmark. This fish was the first vertebrate to evolve since it had a primitive albeit functioning spine.
Behaviour and traitsEdit
Haikouichthys lived in shoals of over 100 individuals. Since they were primarily carnivorous, they fed on the open wounds of other animals, like an injured Anomalocaris after a duel. The fish would bury their faces into the slash until they ate a sufficient amount of meat.
Haikouichthys' method of locomotion was to move its body in a side-to-side motion. This style of movement allowed it to dart away from potential danger.
A shoal of Haikouichthys attacked an Anomalocaris who has very recently lost a duel with another of its kind. The shoal fed on a open wound the arthropod possessed until they all had their fill and swam off.